1. Field of the Invention
The present invention relates to a thermosetting resin, in particular to a thermosetting resin capable of expediting thermosetting process and enhancing the Tg of prepregs and clad laminates.
2. Description of the Prior Art
In a technology related to the manufacture of semi-finished goods of printed circuit boards, fiberglass cloth containing a prepreg (PP) formed by drying a soaked resin, and then the prepreg is combined with copper to form a so-called copper clad laminate or a non-copper clad laminate by a thermal pressing method. According to the electric properties and the requirements of the products, an increasingly higher heat resistance is required, and thus the glass transition temperature Tg of the required materials is increased gradually as well.
A prior art as disclosed in R.O.C. Pat. No. I259187 delays and controls the reaction of a catalyst by boric acid to improve the solidification density of epoxy resin to enhance the effect of Tg, and whose principle is to use coordination bonds of oxalic acid and imidazole to suppress the catalysis of imidazole at a low temperature, and fully catalyze imidazole at a high temperature when oxalic acid and imidazole are separated. This method does not require the general resin curing agent, but the way of delaying the solidification time to improve the solidification density is not helpful to the mass production of the product, particularly in the present efficient world, and this method increases the time and cost. Although the Tg can be improved by using imidazole to catalyze a polyester structure formed by a ring-opening reaction of epoxy resin, yet the moisture absorption or heat resistance of the structure still need feasible solutions.